Specific Heat
The most basic thermal property is specific heat (cp). The p subscript indicates that the value is the specific heat at constant pressure. The specific heat of any material is the amount of heat required to raise one unit of mass of the material by one degree. The most commonly used units for specific heat are kJ/(kg-K), Btu/(lb-F), and cal/(g-K). An important equation relating specific heat, mass of the sample (M), the amount of heat that must be added (Q), and the initial and final temperatures of the sample (T1 and T2) is seen below.
There are several equations that can be used to predict unknown specific heats for food and agricultural products. The first two equations are based on the wet basis moisture content (M) of the product. Wet basis moisture content, introduced here, will be covered more extensively in a later section. For the sake of these equations use wet basis moisture content in decimal (rather than percentage) form. These equations predict specific heat in kJ/(kg-K).
Above freezing: cp = 0.837 + 3.348M
Below freezing: cp = 0.837 + 1.256M
Another equation commonly used to estimate the specific heat for foods in kJ/(kg-K) takes into account the mass fraction (X) of all of the solids that compose the product. As seen as subscripts in the following equation, w is water, p protein, f fat, c carbohydrate, and a ash.
cp = 4.180Xw + 1.711Xp + 1.928Xf + 1.547Xc + 0.908Xa
Alternative Energy
Tidal Energy
Tidal energys similar to hydroelectric energy, but instead of using the fall of water down a stream or river, you would use the tides caused by the moon's gravitational pull.
Pros and Cons
Pros:
Predictable - scientist know exactly howmuch energy is possible to get out of the tides (see equation below)
Efficiant
Powerful - the total energy harnessed from the tides could power two earths.
24 hours - the tides can be harnessed day and night, unlike solar power.
Cons:
Expensive
Sometimes the turbines break under the force of the tides
The energy available from these kinetic systems can be expressed as:
P = Cp x 0.5 x ρ x A x V³
where:
Cp is the turbine coefficient of performance
P = the power generated (in watts)
ρ = the density of the water (seawater is 1025 kg/m³)
A = the sweep area of the turbine (in m²)
V³ = the velocity of the flow cubed (i.e. V x V x V)
Solar Energy
Two types: Active and Passive
Pros and Cons
Pros:
No Pollution — It does not release carbon dioxide, sulfur dioxide, nitrogen oxide or mercury into the atmosphere. It does not burn fuel and generates no emissions.
Saves you Money — Well, after the initial investment, since you’ll be using less energy, your utility bills will be much lower and often times there won’t be an amount due at all.
Less Consumption — Because it requires no fuel, you will save money on the cost of gasoline.
Tax Breaks — The U.S. government offers a tax credit of up $2,000. Start by looking up DSIRE, a database by state of incentives for renewable energy.
Nearly Maintenance Free — Manufacturers are offering warranties of 20 years and more.
Energy Credits — You can build a credit of energy if your solar system produces more energy than you use. Check out net metering, a program that gives you credit for excess electricity, and actually spins your meter backwards.
It is Sustainable and Renewable — Fossil fuels such as coal, oil and natural gas are non renewable and dwindling. Solar energy will never run out.
The Noise Factor — They are silent and have no moving parts.
Cons:
$$$ — The main disadvantage is the price. The panels and installation have high starting costs.
Climate Variability — Although solar energy can be used in most climates, the number of hours of sunlight will determine the number of panels you’ll need and what the wattage of power will be.
Aesthetics — Solar panels take up quite a bit of roof space and to some and aren’t pleasant to look at.
Not 24 Hours — They only work when the sun is shining. At night you will have to rely on stored energy from net metering or have an alternative system.
Solar energy is the radiant light and heat from the Sun that has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation along with secondary solar resources such as wind and wave power, hydroelectricity and biomass account for most of the available renewable energy on Earth. Only a minuscule fraction of the available solar energy is used.
Geothermal Energy
Roots
geo- comes from Greek. Means Earth.
thermal- comes from the Greek word therme, or heat
Energy
Geothermal energy is the process of using the Earth's heat to create energy. Process:
1. Water is put deep in the Earth.
2. Steam goes up through tube.
3. Steam turns turbine.
4. Steam goes through condenser and turns to water.
5. Water goes back into Earth.
Pros and Cons
Pros:
1. Safe
2. Cheap
3. Efficient
Cons:
1. Need more than one well
2. May cause earthquakes
3. Minor damage can take a millenia to fix
Wind Energy
Basically, wind power has a number of advantages and provides an inexpensive, self-reliant method of generating electricity with relatively little maintenance. However, there are some disadvantages with regard to birds, thunderstorms, and the appearance of turbines. It is not always windy, so a combination of solar and/or hydroelectric with wind power can provide a more consistent supply of renewable energy.
Pros and Cons:
Pros:
1. Although wind turbines can be very tall each takes up only a small plot of land. This means that the land below can still be used. This is especially the case in agricultural areas as farming can still continue.
2. Many people find wind farms an interesting feature of the landscape.
3. Remote areas that are not connected to the electricity power grid can use wind turbines to produce their own supply.
4. Wind turbines are available in a range of sizes which means a vast range of people and businesses can use them. Single households to small towns and villages can make good use of range of wind turbines available today. 5. The use of wind turbines does not generate pollution or radioactive waste like most other forms of electricity generation do. Their construction and installation has less environmental impact as well.
6. Wind power may be used to provide electricity to individual homes or other facilities on a self-reliant basis, with no need for fuel or other materials to be supplied. If a natural disaster severs power lines, residents with windmills will not lose their supply of electricity.
7. Wind can also generate power for large numbers of people, using larger turbines connected to an electrical grid. This allows individuals to take advantage of some of their benefits without personally owning or maintaining the equipment.
8. Another one of its advantages is that this type of power generation does not consume any non-renewable resources, like coal, natural gas, or oil. Thus, it won't contribute to their eventual depletion, nor does it promote environmental harm brought about by obtaining these resources.
Cons:
1. The strength of the wind is not constant and it varies from zero to storm force. This means that wind turbines do not produce the same amount of electricity all the time. There will be times when they produce no electricity at all.
2. Many people feel that the countryside should be left untouched, without these large structures being built. The landscape should left in its natural form for everyone to enjoy. Many people also see large wind turbines as unsightly structures and not pleasant or interesting to look at. Some people consider the turbines to have an undesirable appearance, especially when there are very tall units and/or large groups of them. The same could be said for coal or nuclear power plants, but these are concentrated into a smaller number of facilities.
3. Wind turbines are noisy. Each one can generate the same level of noise as a family car travelling at 70 mph.
4. The manufacturing of wind turbines indirectly cause polution.
5. Large wind farms are needed to provide entire communities with enough electricity. For example, the largest single turbine available today can only provide enough electricity for 475 homes, when running at full capacity. How many would be needed for a town of 100 000 people? 6. Another of the disadvantages is that they can be damaged in thunderstorms, partially because of their tall, thin shape. The website of the National Lightning Safety Institute indicates that most damage to wind turbines is caused by lightening. This is more of a problem in warmer parts of the world, where they are frequent.
7. The blades of wind turbines can hit birds who attempt to fly between them. However, it should be kept in mind that birds are also affected by the disadvantages of other power generation methods, especially pollution.
Physical Science Lab
Coaches & Volunteers-Team-
==Resources- ----
SO Events-Physical Science Lab
http://apps1.eere.energy.gov/education/lessonplans/pdfs/wind_turbinebladedesign.pdf
http://www.windstuffnow.com/main/blade_design_help.htm
http://www.kidwind.org/lessons/SFBladeDesign.html
http://www.sciencetoymaker.org/plane/propeller.htm
http://www.thewoodcrafter.net/dirs/props.pdf
http://www.windpower.org/en/tour/design/concepts.htm
http://www.windpower.org/en/tour/design/concepts.htm
http://www.windpower.org/en/tour/design/concepts.htm
http://windwithmiller.windpower.org/en/kids/index.htm I found this and thought that it might be helpful, all about how wind turbined work.
http://girardchem1.wikispaces.com/Biomass+Pros+and+Cons- Prapti S. This website is from a wiki and it has pros and cons of all of the energy ==
http://www.alliantenergykids.com/index.htm
http://www.awea.org/
http://www.darvill.clara.net/altenerg/tidal.htm
http://www.wisc-online.com/objects/ViewObject.aspx?ID=SCE304 - about heat transfer
http://www.brainpop.com/science/energy/ - this site has a lot of helpull information
Physics Science Lab is an old event. Here is one of the old tests: http://physics.weber.edu/carroll/Olympiad/scioly03.pdf
Current Topic to Research-
Energy
Work
Heat
Heat Transfer
Temprature/Temprature Scales
Thermal Energy
Insulation
Energy Conservation Practives
Equations (heat loss, heat gain, specific heat, heat transfer, etc.)
look at http://www.fordhamprep.org/gcurran/sho/sho/lessons/lesson210.htm
http://www.chem.uiuc.edu/webFunChem/SpecificHeat/plastic9.htm
Specific HeatThe most basic thermal property is specific heat (cp). The p subscript indicates that the value is the specific heat at constant pressure. The specific heat of any material is the amount of heat required to raise one unit of mass of the material by one degree. The most commonly used units for specific heat are kJ/(kg-K), Btu/(lb-F), and cal/(g-K). An important equation relating specific heat, mass of the sample (M), the amount of heat that must be added (Q), and the initial and final temperatures of the sample (T1 and T2) is seen below.
There are several equations that can be used to predict unknown specific heats for food and agricultural products. The first two equations are based on the wet basis moisture content (M) of the product. Wet basis moisture content, introduced here, will be covered more extensively in a later section. For the sake of these equations use wet basis moisture content in decimal (rather than percentage) form. These equations predict specific heat in kJ/(kg-K).
Above freezing: cp = 0.837 + 3.348M
Below freezing: cp = 0.837 + 1.256M
Another equation commonly used to estimate the specific heat for foods in kJ/(kg-K) takes into account the mass fraction (X) of all of the solids that compose the product. As seen as subscripts in the following equation, w is water, p protein, f fat, c carbohydrate, and a ash.
cp = 4.180Xw + 1.711Xp + 1.928Xf + 1.547Xc + 0.908Xa
Alternative Energy
Tidal Energy
Tidal energys similar to hydroelectric energy, but instead of using the fall of water down a stream or river, you would use the tides caused by the moon's gravitational pull.
Pros and Cons
Pros:
Cons:
The energy available from these kinetic systems can be expressed as:
P = Cp x 0.5 x ρ x A x V³
where:
Cp is the turbine coefficient of performance
P = the power generated (in watts)
ρ = the density of the water (seawater is 1025 kg/m³)
A = the sweep area of the turbine (in m²)
V³ = the velocity of the flow cubed (i.e. V x V x V)
Solar Energy
Two types: Active and PassivePros and Cons
Pros:
Cons:
- $$$ — The main disadvantage is the price. The panels and installation have high starting costs.
- Climate Variability — Although solar energy can be used in most climates, the number of hours of sunlight will determine the number of panels you’ll need and what the wattage of power will be.
- Aesthetics — Solar panels take up quite a bit of roof space and to some and aren’t pleasant to look at.
- Not 24 Hours — They only work when the sun is shining. At night you will have to rely on stored energy from net metering or have an alternative system.
http://earth911.com/blog/2007/10/15/pros-and-cons-of-solar-power/Solar energy is the radiant light and heat from the Sun that has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation along with secondary solar resources such as wind and wave power, hydroelectricity and biomass account for most of the available renewable energy on Earth. Only a minuscule fraction of the available solar energy is used.
Geothermal Energy
Roots
geo- comes from Greek. Means Earth.thermal- comes from the Greek word therme, or heat
Energy
Geothermal energy is the process of using the Earth's heat to create energy. Process:1. Water is put deep in the Earth.
2. Steam goes up through tube.
3. Steam turns turbine.
4. Steam goes through condenser and turns to water.
5. Water goes back into Earth.
Pros and Cons
Pros:
1. Safe2. Cheap
3. Efficient
Cons:
1. Need more than one well2. May cause earthquakes
3. Minor damage can take a millenia to fix
Wind Energy
Basically, wind power has a number of advantages and provides an inexpensive, self-reliant method of generating electricity with relatively little maintenance. However, there are some disadvantages with regard to birds, thunderstorms, and the appearance of turbines. It is not always windy, so a combination of solar and/or hydroelectric with wind power can provide a more consistent supply of renewable energy.
Pros and Cons:
Pros:
1. Although wind turbines can be very tall each takes up only a small plot of land. This means that the land below can still be used. This is especially the case in agricultural areas as farming can still continue.2. Many people find wind farms an interesting feature of the landscape.
3. Remote areas that are not connected to the electricity power grid can use wind turbines to produce their own supply.
4. Wind turbines are available in a range of sizes which means a vast range of people and businesses can use them. Single households to small towns and villages can make good use of range of wind turbines available today.
5. The use of wind turbines does not generate pollution or radioactive waste like most other forms of electricity generation do. Their construction and installation has less environmental impact as well.
6. Wind power may be used to provide electricity to individual homes or other facilities on a self-reliant basis, with no need for fuel or other materials to be supplied. If a natural disaster severs power lines, residents with windmills will not lose their supply of electricity.
7. Wind can also generate power for large numbers of people, using larger turbines connected to an electrical grid. This allows individuals to take advantage of some of their benefits without personally owning or maintaining the equipment.
8. Another one of its advantages is that this type of power generation does not consume any non-renewable resources, like coal, natural gas, or oil. Thus, it won't contribute to their eventual depletion, nor does it promote environmental harm brought about by obtaining these resources.
Cons:
1. The strength of the wind is not constant and it varies from zero to storm force. This means that wind turbines do not produce the same amount of electricity all the time. There will be times when they produce no electricity at all.2. Many people feel that the countryside should be left untouched, without these large structures being built. The landscape should left in its natural form for everyone to enjoy. Many people also see large wind turbines as unsightly structures and not pleasant or interesting to look at. Some people consider the turbines to have an undesirable appearance, especially when there are very tall units and/or large groups of them. The same could be said for coal or nuclear power plants, but these are concentrated into a smaller number of facilities.
3. Wind turbines are noisy. Each one can generate the same level of noise as a family car travelling at 70 mph.
4. The manufacturing of wind turbines indirectly cause polution.
5. Large wind farms are needed to provide entire communities with enough electricity. For example, the largest single turbine available today can only provide enough electricity for 475 homes, when running at full capacity. How many would be needed for a town of 100 000 people?
6. Another of the disadvantages is that they can be damaged in thunderstorms, partially because of their tall, thin shape. The website of the National Lightning Safety Institute indicates that most damage to wind turbines is caused by lightening. This is more of a problem in warmer parts of the world, where they are frequent.
7. The blades of wind turbines can hit birds who attempt to fly between them. However, it should be kept in mind that birds are also affected by the disadvantages of other power generation methods, especially pollution.
http://hubpages.com/hub/advantages-disadvantages-wind
Biomass Energy